阅读说明：本技术 一种铝合金缓冲的环保阻燃耐火电力电缆 (Environment-friendly flame-retardant fire-resistant power cable buffered by aluminum alloy ) 是由 陆春良 王国权 王惠兵 冯成 席娇娜 于 2021-08-03 设计创作，主要内容包括：本发明提供了一种铝合金缓冲的环保阻燃耐火电力电缆,所述电缆从外向内依次包括外保护层、阻燃层、铝合金缓冲层、内保护层和导体缆芯,其中铝合金缓冲层中包括泡沫铝合金作为基体以及填充在泡沫铝合金中填充材料；本发明采用了多层复合结构以及改性的保护层成分,提高了电缆的耐折弯性能、耐撞击性和阻燃性,本发明的铝合金缓冲的环保阻燃耐火电力电缆不仅具有良好的耐撞击缓冲性能,可以改善电缆的柔软性、提高电缆的弯曲性能,并且在高温状态下铝合金缓冲层能够受热膨胀,从而进一步隔绝外部的热量传导到电芯,具有良好的隔热和阻燃效果,并且本发明的铝合金缓冲的环保阻燃耐火电力电缆具有结构简单、机械性能好,耐折弯,阻燃效果好,成本低廉等优点。(The invention provides an aluminum alloy buffered environment-friendly flame-retardant fire-resistant power cable which sequentially comprises an outer protective layer, a flame-retardant layer, an aluminum alloy buffer layer, an inner protective layer and a conductor cable core from outside to inside, wherein the aluminum alloy buffer layer comprises foamed aluminum alloy serving as a matrix and filling materials filled in the foamed aluminum alloy; the environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy has good impact-resistant buffering performance, can improve the flexibility of the cable and improve the bending performance of the cable, and can expand under the heating of the aluminum alloy buffer layer in a high-temperature state, so that external heat is further isolated from being conducted to a battery cell, and the environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy has good heat insulation and flame-retardant effects.)

1. The environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy comprises an outer protective layer, a flame-retardant layer, an aluminum alloy buffer layer, an inner protective layer and a conductor cable core from outside to inside in sequence, and is characterized in that the expansion rate of the aluminum alloy buffer layer at high temperature is 3.5-4.2 times, and the aluminum alloy buffer layer comprises foamed aluminum alloy serving as a matrix and filling materials filled in the foamed aluminum alloy; the filling material comprises the following components in parts by mass: 24-32 parts of kaolin, 12-14 parts of diatomite, 18-20 parts of aluminum hydroxide, 6-8 parts of modified expandable graphite, 30-35 parts of pentaerythritol, 15-20 parts of melamine polyphosphate, 15-20 parts of melamine, 6-10 parts of phenolic resin powder and 1-3 parts of guar gum; the flame-retardant layer comprises the following components in parts by mass: 60-65 parts of methyl vinyl silicone rubber with the number average molecular weight of 60-80 ten thousand, 12-14 parts of 2, 4-dichloro benzoyl peroxide, 10-12 parts of polyphenylsulfone terephthalamide, 5-8 parts of polyether ether ketone, 5-6 parts of vinyl tri (beta-methoxyethoxy) silane, 4-5 parts of vinyl triethoxysilane, 5-8 parts of sodium metaaluminate, 8-10 parts of mica powder and 8-10 parts of montmorillonite.

2. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1, wherein the foamed aluminum alloy is an aluminum titanium alloy having a porosity of 75-80%; the aluminum alloy buffer layer is prepared by the following method: and dispersing a filling material in deionized water to obtain filling slurry, then dipping the aluminum-titanium alloy in the filling slurry, taking out and drying to obtain the aluminum alloy buffer layer.

3. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1, wherein the outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of polyvinyl chloride to 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14-15: 1.

4. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1 wherein the inner protective layer is a composite of polystyrene and modified silica particles, wherein the modified silica particles have an average particle size of 300-400 microns and are prepared by the following method: 50 parts by mass of silica particles with the particle size of 300-400 microns are put into 100 parts by mass of NaOH solution with the concentration of 0.3mol/L, stirred at the constant temperature of 85 ℃ for 4 hours, washed by deionized water and dried, then 10 parts by mass of silica particles are put into 100 parts by mass of toluene solution containing 10 wt% of silane coupling agent KH550, stirred at the constant temperature of 85 ℃ for 4 hours, filtered and dried to obtain the modified silica particles.

5. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1, wherein the modified expandable graphite is prepared by a method comprising: 1) mixing 5 parts by mass of potassium permanganate with 50 parts by mass of flaky natural graphite, adding 100 parts by mass of mixed acid liquor formed by mixing nitric acid and phosphoric acid according to the mass ratio of 7:3, soaking for 2 hours, washing with deionized water, and then carrying out vacuum drying at 300 ℃ to prepare expandable graphite; 2) adding 5 parts by mass of hexadecyl trimethyl ammonium bromide and 2 parts by mass of sodium bromide into 100 parts by mass of deionized water to obtain a modifier; 3) mixing 15 parts by mass of expandable graphite, 5 parts by mass of modifier and 4 parts by mass of 40 wt% phosphoric acid, ultrasonically mixing for 1 hour in a water bath at 50 ℃, washing with water, drying, and then using 1500KW/m²The modified expanded graphite is obtained by microwave expansion.

6. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1, wherein the filler material is comprised of, by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 7 parts of modified expandable graphite, 32 parts of pentaerythritol, 18 parts of melamine polyphosphate, 18 parts of melamine, 8 parts of phenolic resin powder and 2 parts of guar gum.

7. The aluminum alloy buffered, environmentally friendly, flame retardant, fire resistant power cable of claim 1, wherein the flame retardant layer is comprised of the following components in parts by mass: 62 parts of methyl vinyl silicone rubber with the number average molecular weight of 70 ten thousand, 13 parts of 2, 4-dichloroperoxybenzoyl, 111 parts of polyphenylsulfone terephthalamide, 6 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 6 parts of sodium metaaluminate, 9 parts of mica powder and 9 parts of montmorillonite.

Technical Field

The invention relates to the technical field of power cables, in particular to an aluminum alloy buffered environment-friendly flame-retardant fire-resistant power cable.

Background

A cable generally refers to a conductor made of one or more conductors insulated from each other and an outer insulating layer to transmit power or information from one place to another. The most basic performance of the cable is to be able to effectively transmit power, electromagnetic waves, light waves and the like, and to have certain adaptability to the use environment. In order to adapt a cable for different applications, it is necessary to have a wide range of properties, combining: the conductor in the cable has good conductive performance, and the optical fiber has good light wave conduction without great loss; the coating material is required to have good electrical insulation performance, such as insulation resistance, dielectric constant, dielectric loss, breakdown voltage and the like.

The flame-retardant cable is a cable which is characterized in that a test sample is burnt under a specified test condition, after a test fire source is removed, the flame spread is only in a limited range, and residual flame or residual ignition can be self-extinguished within a limited time. The fundamental characteristic is that the fire may burn out and fail to operate in case of fire, but the fire may be prevented from spreading. In common, in case of fire, the electric wire can limit the combustion within a local range, does not spread, keeps other various equipment and avoids causing larger loss.

The sheath layer of the flame-retardant cable generally has the following two characteristics: high heat dissipating and self incombustibility, cable sheathing is generally made by the rubber material, the rubber material has toughness and elasticity, under repetitious buckling many times, the crackle also can not appear in the lateral wall of rubber, be cable sheathing's ideal material, add inorganic powder in the used rubber material of cable sheathing, incombustibility through inorganic powder improves the fire resistance on cable sheathing layer, advanced scientific meaning has, not only the fire resistance of rubber material cable sheathing has been improved, reduce the quantity of rubber simultaneously and improve cable sheathing's wearability. However, after inorganic particles are added to the rubber of the cable sheath, the bonding force between the rubber and the inorganic particles is poor, and the sheath layer is easy to crack under the condition that the cable is repeatedly bent, so that the cable loses the protection effect prematurely.

Nowadays, the manufacture of the flame-retardant fire-resistant environment-friendly insulated cable in China is still in the primary stage, and the technical level and the processing level of each cable manufacturer in China are different, but the requirement of the environment-friendly flame-retardant fire-resistant insulated cable is strict, and the technical level of the flame-retardant and fire-resistant cable is gradually improved along with the continuous development of the flame-retardant technology in China, but the flame-retardant and fire-resistant cables have high cost and are complex to lay and use, and the safety and the reliability of the cables are far from the requirements. The cable can be ensured to normally run in a high-temperature environment so as to meet the requirements of modern society and scientific and technological development, and the cable is a technical problem which is urgently needed to be solved by cable production enterprises at present.

Disclosure of Invention

The invention provides an aluminum alloy buffered environment-friendly flame-retardant fire-resistant power cable which sequentially comprises an outer protective layer, a flame-retardant layer, an aluminum alloy buffer layer, an inner protective layer and a conductor cable core from outside to inside, wherein the aluminum alloy buffer layer comprises foamed aluminum alloy serving as a matrix and filling materials filled in the foamed aluminum alloy; the environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy has good impact-resistant buffering performance, can improve the flexibility of the cable and improve the bending performance of the cable, and can expand under the heating of the aluminum alloy buffer layer in a high-temperature state, so that external heat is further isolated from being conducted to a battery cell, and the environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy has good heat insulation and flame-retardant effects. The specific scheme is as follows:

the environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy comprises an outer protective layer, a flame-retardant layer, an aluminum alloy buffer layer, an inner protective layer and a conductor cable core from outside to inside in sequence, wherein the expansion rate of the aluminum alloy buffer layer at high temperature is 3.5-4.2 times, and the aluminum alloy buffer layer comprises foamed aluminum alloy serving as a matrix and a filling material filled in the foamed aluminum alloy; the filling material comprises the following components in parts by mass: 24-32 parts of kaolin, 12-14 parts of diatomite, 18-20 parts of aluminum hydroxide, 6-8 parts of modified expandable graphite, 30-35 parts of pentaerythritol, 15-20 parts of melamine polyphosphate, 15-20 parts of melamine, 6-10 parts of phenolic resin powder and 1-3 parts of guar gum; the flame-retardant layer comprises the following components in parts by mass: 60-65 parts of methyl vinyl silicone rubber with the number average molecular weight of 60-80 ten thousand, 12-14 parts of 2, 4-dichloro benzoyl peroxide, 10-12 parts of polyphenylsulfone terephthalamide, 5-8 parts of polyether ether ketone, 5-6 parts of vinyl tri (beta-methoxyethoxy) silane, 4-5 parts of vinyl triethoxysilane, 5-8 parts of sodium metaaluminate, 8-10 parts of mica powder and 8-10 parts of montmorillonite.

Further, the foamed aluminum alloy is an aluminum-titanium alloy, and the porosity is 75-80%; the aluminum alloy buffer layer is prepared by the following method: and dispersing a filling material in deionized water to obtain filling slurry, then dipping the aluminum-titanium alloy in the filling slurry, taking out and drying to obtain the aluminum alloy buffer layer.

Further, the outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14-15: 1.

Further, the inner protection layer is a composite of polystyrene and modified silica particles, wherein the average particle size of the modified silica particles is 300-400 microns, and the modified silica particles are prepared by the following method: 50 parts by mass of silica particles with the particle size of 300-400 microns are put into 100 parts by mass of NaOH solution with the concentration of 0.3mol/L, stirred at the constant temperature of 85 ℃ for 4 hours, washed by deionized water and dried, then 10 parts by mass of silica particles are put into 100 parts by mass of toluene solution containing 10 wt% of silane coupling agent KH550, stirred at the constant temperature of 85 ℃ for 4 hours, filtered and dried to obtain the modified silica particles.

Further, the modified expandable graphite is prepared by the following preparation method: 1) mixing 5 parts by mass of potassium permanganate with 50 parts by mass of flaky natural graphite, adding 100 parts by mass of mixed acid liquor formed by mixing nitric acid and phosphoric acid according to the mass ratio of 7:3, soaking for 2 hours, washing with deionized water, and then carrying out vacuum drying at 300 ℃ to prepare expandable graphite; 2) adding 5 parts by mass of hexadecyl trimethyl ammonium bromide and 2 parts by mass of sodium bromide into 100 parts by mass of deionized water to obtain a modifier; 3) according to parts by mass, 15 parts by mass of expandable graphite, 5 parts by mass of modifier and 4 parts by mass of 40 wt% phosphoric acid are mixed, ultrasonically mixed for 1 hour in a water bath at 50 ℃, washed with water, dried and then expanded by using 1500KW/m2 microwaves to obtain the modified expandable graphite.

Further, the filling material comprises the following components in parts by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 7 parts of modified expandable graphite, 32 parts of pentaerythritol, 18 parts of melamine polyphosphate, 18 parts of melamine, 8 parts of phenolic resin powder and 2 parts of guar gum.

Further, the flame-retardant layer comprises the following components in parts by mass: 62 parts of methyl vinyl silicone rubber with the number average molecular weight of 70 ten thousand, 13 parts of 2, 4-dichloroperoxybenzoyl, 111 parts of polyphenylsulfone terephthalamide, 6 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 6 parts of sodium metaaluminate, 9 parts of mica powder and 9 parts of montmorillonite.

The invention has the following beneficial effects:

1) according to the invention, the aluminum alloy buffer layer is added into the cable, and the aluminum alloy buffer layer and the flame-retardant layer jointly form a bending-resistant, impact-resistant and flame-retardant composite layer of the cable, the aluminum-titanium alloy has a good memory effect, and provides a matrix skeleton effect in the buffer layer, so that the bending resistance, bending resistance and impact resistance are improved, meanwhile, heat generated in the electric core during electric power conduction can be timely conducted to the outside, a heat dissipation effect is achieved, the electric core is prevented from being damaged due to local heat release, and after the outside is ignited, the filler in the buffer layer can expand by more than 3 times at high temperature, so that the heat conduction of the buffer layer is effectively blocked, and the effect of shielding external heat from being transferred to the electric core is achieved;

2) the material in the flame-retardant layer can play a flame-retardant role, can better protect the conductor and prevent the conductor from being damaged due to high-temperature burning, and the most important core role is to improve the mechanical bonding performance between the flame-retardant layer and the buffer layer, improve the flexibility of the cable and further greatly improve the bending performance of the composite cable;

3) the modified silicon dioxide material improves the dispersion suspension property of silicon dioxide particles due to the action of a macromolecular chain of a silicon dioxide surface coupling agent, the absolute value of the potential of the modified silicon dioxide is increased, the electrostatic repulsion between the particles is increased, the dispersion suspension property of the silicon dioxide in a rubber solution is further improved, and the amino (-NH2) of a silane coupling agent KH550 can be combined with polystyrene by chemical bonds, so that the silicon dioxide particles are combined more firmly.

4) The 2, 4-dichloroperoxybenzoyl, the polyphenylsulfone terephthalamide, the polyether-ether-ketone, the sodium metaaluminate, the mica powder and the montmorillonite are mixed to be used as a flame retardant, so that the effective weight of the cable is effectively reduced, the cable is lighter and more handy, the fire-resistant insulating property of the cable is greatly improved, the cable is harder under the condition of high-temperature firing, the flame-retardant effect is enhanced, and the cable is better in heat resistance and bending resistance.

5) The modified expanded graphite can play a part of catalytic action on the carbonization of pentaerythritol, the carbonization effect of the pentaerythritol is improved, and the fire resistance of the layer can be further improved by the modified expanded graphite.

Detailed Description

The present invention will be described in more detail below with reference to specific examples, but the scope of the present invention is not limited to these examples.

The environment-friendly flame-retardant fire-resistant power cable buffered by the aluminum alloy of the embodiment sequentially comprises from outside to inside: outer protective layer, fire-retardant layer, aluminum alloy buffer layer, interior protective layer and conductor cable core. Wherein, the outer protective layer is 0.5mm, the flame retardant layer is 1mm, the aluminum alloy buffer layer is 1mm, the inner protective layer is 0.5mm and the diameter of the conductor cable core is 7.5 mm.

The aluminum alloy buffer layer is prepared by the following method: and dispersing a filling material in deionized water to obtain filling slurry, then dipping the aluminum-titanium alloy in the filling slurry, taking out and drying to obtain the aluminum alloy buffer layer.

The modified silicon dioxide particles are prepared by the following method: 50 parts by mass of silica particles with the particle size of 300-400 microns are put into 100 parts by mass of NaOH solution with the concentration of 0.3mol/L, stirred at the constant temperature of 85 ℃ for 4 hours, washed by deionized water and dried, then 10 parts by mass of silica particles are put into 100 parts by mass of toluene solution containing 10 wt% of silane coupling agent KH550, stirred at the constant temperature of 85 ℃ for 4 hours, filtered and dried to obtain the modified silica particles.

The modified expandable graphite is prepared by the following preparation method: 1) mixing 5 parts by mass of potassium permanganate with 50 parts by mass of flaky natural graphite, adding 100 parts by mass of mixed acid liquor formed by mixing nitric acid and phosphoric acid according to the mass ratio of 7:3, soaking for 2 hours, washing with deionized water, and then carrying out vacuum drying at 300 ℃ to prepare expandable graphite; 2) adding 5 parts by mass of hexadecyl trimethyl ammonium bromide and 2 parts by mass of sodium bromide into 100 parts by mass of deionized water to obtain a modifier; 3) according to parts by mass, 15 parts by mass of expandable graphite, 5 parts by mass of modifier and 4 parts by mass of 40 wt% phosphoric acid are mixed, ultrasonically mixed for 1 hour in a water bath at 50 ℃, washed with water, dried and then expanded by using 1500KW/m2 microwaves to obtain the modified expandable graphite.

Example 1

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14: 1.

The flame-retardant layer comprises the following components in parts by mass: 60 parts of methyl vinyl silicone rubber with the number average molecular weight of 60 ten thousand, 12 parts of 2, 4-dichloro benzoyl peroxide, 10 parts of polyphenylsulfone terephthalamide, 5 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 4 parts of vinyl triethoxysilane, 5 parts of sodium metaaluminate, 8 parts of mica powder and 8 parts of montmorillonite;

the foamed aluminum alloy is aluminum-titanium alloy, and the porosity is 75%; the filling material comprises the following components in parts by mass: 24 parts of kaolin, 12 parts of diatomite, 18 parts of aluminum hydroxide, 6 parts of modified expandable graphite, 30 parts of pentaerythritol, 15 parts of melamine polyphosphate, 15 parts of melamine, 6 parts of phenolic resin powder and 1 part of guar gum;

the inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 300 micrometers.

Example 2

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 15: 1.

The flame-retardant layer comprises the following components in parts by mass: 65 parts of methyl vinyl silicone rubber with the number average molecular weight of 80 ten thousand, 14 parts of 2, 4-dichloroperoxybenzoyl, 12 parts of polyphenylsulfone terephthalamide, 8 parts of polyether-ether-ketone, 6 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 8 parts of sodium metaaluminate, 10 parts of mica powder and 10 parts of montmorillonite;

the foamed aluminum alloy is an aluminum-titanium alloy, and the porosity is 80%; the filling material comprises the following components in parts by mass: 32 parts of kaolin, 14 parts of diatomite, 20 parts of aluminum hydroxide, 8 parts of modified expandable graphite, 35 parts of pentaerythritol, 20 parts of melamine polyphosphate, 20 parts of melamine, 10 parts of phenolic resin powder and 3 parts of guar gum;

the inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 400 micrometers.

Example 3

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14: 1.

The flame-retardant layer comprises the following components in parts by mass: 62 parts of methyl vinyl silicone rubber with the number average molecular weight of 70 ten thousand, 13 parts of 2, 4-dichloroperoxybenzoyl, 111 parts of polyphenylsulfone terephthalamide, 6 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 6 parts of sodium metaaluminate, 9 parts of mica powder and 9 parts of montmorillonite;

the foamed aluminum alloy is aluminum-titanium alloy, and the porosity is 75-80%; the filling material comprises the following components in parts by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 7 parts of modified expandable graphite, 32 parts of pentaerythritol, 18 parts of melamine polyphosphate, 18 parts of melamine, 8 parts of phenolic resin powder and 2 parts of guar gum.

The inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 350 micrometers.

Comparative example 1

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14: 1.

The foamed aluminum alloy is aluminum-titanium alloy, and the porosity is 75-80%; the filling material comprises the following components in parts by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 7 parts of modified expandable graphite, 32 parts of pentaerythritol, 18 parts of melamine polyphosphate, 18 parts of melamine, 8 parts of phenolic resin powder and 2 parts of guar gum.

The inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 350 micrometers.

Comparative example 2

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14: 1.

The flame-retardant layer comprises the following components in parts by mass: 62 parts of methyl vinyl silicone rubber with the number average molecular weight of 70 ten thousand, 13 parts of 2, 4-dichloroperoxybenzoyl, 111 parts of polyphenylsulfone terephthalamide, 6 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 6 parts of sodium metaaluminate, 9 parts of mica powder and 9 parts of montmorillonite;

the buffer layer material comprises the following components in parts by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 7 parts of modified expandable graphite, 32 parts of pentaerythritol, 18 parts of melamine polyphosphate, 18 parts of melamine, 8 parts of phenolic resin powder and 2 parts of guar gum.

The inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 350 micrometers.

Comparative example 3

The outer protective layer is a mixture of polyvinyl chloride and 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide, wherein the mass ratio of the polyvinyl chloride to the 3- [2- (3, 5-dimethyl-2-oxocyclohexyl) -2-hydroxyethyl ] glutarimide is 14: 1.

The flame-retardant layer comprises the following components in parts by mass: 62 parts of methyl vinyl silicone rubber with the number average molecular weight of 70 ten thousand, 13 parts of 2, 4-dichloroperoxybenzoyl, 111 parts of polyphenylsulfone terephthalamide, 6 parts of polyether-ether-ketone, 5 parts of vinyl tri (beta-methoxyethoxy) silane, 5 parts of vinyl triethoxysilane, 6 parts of sodium metaaluminate, 9 parts of mica powder and 9 parts of montmorillonite;

the foamed aluminum alloy is aluminum-titanium alloy, and the porosity is 75-80%; the filling material comprises the following components in parts by mass: 28 parts of kaolin, 13 parts of diatomite, 19 parts of aluminum hydroxide, 8 parts of phenolic resin powder and 2 parts of guar gum.

The inner protective layer is a composite of polystyrene and modified silicon dioxide particles, the mass ratio of the polystyrene to the modified silicon dioxide particles is 10:1, and the average particle size of the modified silicon dioxide particles is 350 micrometers.

Test and results

Flame retardant performance part 21 of the cable line integrity test under flame conditions according to GB/T19216.21-2003; test procedures and required rated voltage 0.6/1.0kV and below cable (GB/T19216.21-2003, IEC60331-21:1999, IDT) were tested. And judging whether the power can be continuously supplied according to the indicating condition of the terminal indicating lamp. The extinguishing time of the indicator lamp is used as an index parameter for measuring the flame retardant effect of the cable, and the longer the extinguishing time of the indicator lamp is, the better the flame retardant effect is.

TABLE 1

	Time of extinguishing indicator lamp (min)
		Example 1	267
Example 2	259
		Example 3	281
Comparative example 1	185
		Comparative example 2	223
Comparative example 3	116

The bending resistance of the material was tested by bending the cable 90 degrees 3000 times to and fro and observing the surface state of the cable.

TABLE 2

	Bending Property, appearance
		Example 1	Good effect
Example 2	Good effect
		Example 3	Good effect
Comparative example 1	Crack(s)
		Comparative example 2	Crack(s)
Comparative example 3	Good effect

The data in tables 1 and 2 show that the bending resistance is obviously deteriorated when the aluminum alloy in the buffer layer is removed or the flame-retardant layer is removed, which indicates that the existence of the aluminum alloy and the flame-retardant layer plays an obvious role in the bending resistance of the material; and when the filling material of the buffer layer can not expand, the buffer layer can have serious inward heat conduction, and the fireproof performance is sharply reduced.

While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention.